Rinse



March 1964 1-. E. JENKINS ETAL 3,

DRAIN CONTROL SYSTEM FOR A WASHING MACHINE 2 Sheets-Sheet 1 Filed Oct.29, 1962 INVENTORS THOMAS E. TEMKlNS N A M F F U A K R m w a M b THEJRATTORNEY Ma h 1964 T. E. JENKINS ETAL 3, 4, 46

DRAIN CONTROL SYSTEM FOR A WASHING MACHINE Filed Oct. 29, 1962- F'lG.3

AUSE PAUSE F'lG.4

INVENTORS THOMAS E. JENKINS B & MELVIN R. KAUF'FMAN THEIR ATTORNEYUnited States Patent 3,124,146 BRAEN CQNTR'UL SYSTEM FOR A WASHINGMACHINE Thorn-as E. .lenlrins and Melvin Kauilinan, Louisville,

Ky, to General Electric Eornpany, a corporation of New York Filed Get.29, 1962, Ser. No. 233,683 2 (Jlaims. (El. 134-57) This inventionrelates to control systems for washing machines, and more particularlyto an improved arrangement, for use primarily in dishwashers, to preventoccurrence of the undesirable noise which results from op eration of thedrain pump after substantially all liquid has been drained out of themachine.

It is an object of our invention to provide a washing machine in which,after a washing operation is provided, the forced drain out operationwill be provided only as long as there is need for it.

in one aspect of our invention we provide a washing machine of the typewhich has an automatic washing cycle. in the usual way, the machine hasa tub, washing means for washing articles in the tub, and a drain pumpfor removing vitiated liquid from the tub together with a drain conduitconnected to the pump. Suitable sequence control means are provided forcausing operation of the washing means and then operation of the pump,with this sequence being repeated a predetermined number of times untilthe sequence control means shuts the machine oil. Together with theforegoing, we provide flow responsive means which is effective, when thedrain pump operates, to terminate operation of the drain pump when thereis no further liquid to be removed by the pump. This is effected,preferably, by having the flow responsive means control a switch in acircuit for causing operation of the drain pump, with the sequencecontrol means giving up control of the drain pump for a predeterminedperiod to the flow responsive means each time after the drain pump hasbeen started.

In the drawings, FIGURE 1 is a side elevational view, with some of theparts broken away to illustrate details, of a dishwasher incorporatingour invention;

FEGURE 2 is an enlarged view in cross section showing part of thestructure of FIGURE 1;

FKGURE 3 is a schematic electrical wiring diagram illustrating ourimproved control system in one form thereof; and

FIGURE 4 is a sequence control cam chart illustrating the sequence ofoperation of the schematically shown switches of FIGURE 3.

Referring now to FTGURE 1, there is shown, for illustrative purposes, aportable automatic dishwasher ll, although our invention will beunderstood to apply equally well to built-in machines. The dishwasherhas a dishwashing compartment 2 formed by a tub 3 with a top opening 4;adapted to be closed by a cover 5 hingedly mounted at the rear of themachine by an assembly 6. The bottom of the tub may have a downwardlysloped portion '7 formin a sump at the center thereof. Tub 3 may haveside walls which continue down almost to the base or the floor on whichthe machine rests so as to form an enclosure or cabinet for the machine.Also, these walls may support casters 8 in any conventional manner so asto make the machine movable.

Within compartment 2 there may be provided a number of dish supportingmembers such as an upper rack 9 and a lower rack ill which are designedso as to support dishes and other eating and cooking articles.Dishwasher It incorporates suitable washing means which in this case isembodied in a rotatable water ejecting member 11 positioned below rackill together with a telescoping member 12 positioned at the center ofmember 11. When under pressure, member 12 rises somewhat and is providedwith apertures in its top so as to eject water with substantial forceagainst dishes in the upper rack 9. At the same time, member ii isrotating under the force of the water and is ejecting that water againstthe dishes in both racks.

Arm l1 and telescoping member 12 form a part of an assembly 13 whichfurther includes a motor 14. The motor 14 operates a pumping assembly 15which may be of conventional design and which receives its water throughan inlet 16 at the very bottom of sump 7. The motor may be of the typewhich, when rotated in one direction, causes the pumping assembly toforce liquid up through members ii and i2, and which when reversedcauses the pumping assembly to act as a drain pump and pass the liquidout to drain, such structures being commercially available and wellknown to those in the art.

In addition, for drying the dishes after they have been cleansed, asuitable electric heating element 17 may be provided in the conventionalmanner. The heating element 17, as well as the motor lid and aconventional water inlet valve (not shown in FIGURE 1) will normally beunder the control of a sequence control assembly (also not physicallyshown in FIGURE 1). The assembly may be secured within the hollow frontwall 18 of the dishwasher, with suitable manually operable members suchas 19 extending so as to be readily accessible to an operator for theselection of a sequence of operations of the machine. A suitablesequence of operations: for the machine is described in connection withPIG- URES 3 and 4 herebelow.

It will be understood that all the components described thus far areconventional, and are provided in dishwashers widely available forpurchase by the public.

Connected to the outlet 2% of pump 15, and leading to a drain, is adrain conduit 21 to which there is secured an assembly 22. Referringparticularly to FEGURE 2, it can be seen that assembly 22 includes aswitch 23 having an operating member or button 24 against which is adiaphragm 25 having its surface 26 constitutin a part of the wall ofconduit 21. When there is no flow through conduit 21 the button is inits extended position as shown, and the switch 2 3 has a first positionfor a purpose to be hereinafter discussed. However, when liquid flowoccurs through conduit 21 as a result of a drain operation, then thepressure of that flow causes the diaphragm 25 to move so as to depressbutton and operate the switch 23.

Referring now to FIGURE 3, there is shown a control circuit embodyingour invention. It will be understood that, besides the componentsspecifically shown, other electrically controlled components of themachine, such as suitable indicating lights and detergent and rinseagent dispensers, will often be controlled electrically. These othercomponents have been left out of FIGURE 2 only in order to show clearlythe invention without confusing additional details which do not form apart thereof.

The circuit is energized through a pair of supply conductors 27 andacross a suitable source of power (not shown) such as the conventionalvolt 60 cycle source generally available. Connected across theconductors 27 and 28 is the timer motor 29 of the sequence controlassembly previously referred to. As shown schematically in FIGURE 3,this sequence control assembly includes the motor 29 in controllingrelationship to a plurality of cams 3%, 31, 32, 33 and 34, with the cams3tl-34 in turn being in controlling relationship to switches 35, 36, 37,38 and 39. In addition, the assembly will normally include the manualcontrol switches previously referred to by the numeral 19 in FIGURE 1.Switch 35' is in series with motor 29 across the conductors 27 and 28 soas to permit energization of the motor 29 when it is closed and preventenergization thereof when it is open. Similarly,

the heating element l? is connected across the conductors 27 and 2Sseries with switch 56, and a solenoid .55 controlling the water valve ofthe machine is connected across the conductors 27 and E3 in series withthe switch 37.

The motor 14- includes a main winding 41 and a pair of start windings 42and When winding 41 and Winding 4-2 are energized at the same time, themotor rotates in the direction appropriate to cause operation of thewashing structures 11 and 12. When windings i1 and 43 are energized atthe same time the motor starts to rotate in the direction effective tocause draining of liquid out of tub 3 through conduit 21. In theconventional manner, a start relay 44 may be provided in series with thewinding 41, in controlling relationship to a contact 45 in series withboth windings 42 and At a relatively high current level, such as thatwhich iiows through the relay 44 when the motor is not rotating, relay 4E closes switch 4-5. As the motor comes up to speed, the level ofenergization drops substantially; as a result, relay 44 lets switch 45move to its normally open position to insure de-energization ofwhichever of windings 42 and 43 was energized. Thus, the motor 1 may becaused to start in either direction of rotation, as will be explained,and then will continue to run on the winding 41 alone after it comes upto speed.

The direction of rotation is determined by switch 39 which is movableinto engagement with either of two contacts 46 and 47 to provide forselection of start windings 42. or 4-3 respectively. Both the startwindings, through switch 39, and the main winding are connected throughswitch 33 so that the entire motor-energizing circuit is connectedacross lines 27 and 28 and is controlled by switch 33. In parallel withswitch 38, there is provided the how responsive switch 23 which is, asshown, normally open, but which moves to a closed position in responseto pressure within drain conduit 21 on diaphragm 25.

Referring now to FIGURE 4, it will be seen that it is intended that aconventional sequence of operations of the machine includes a firstrinse which actually is introduction of water and a brief washingoperation; this may either be with or without detergent, and is followedby draining of that water. A second similar rinse and drain are thenprovided, followed by a wash step which is simply a provision of thewashing operation for a longer period of time with, preferably, asuitable detergent being injected. This wash is then again followed bydrain and then two rinses and drains follow, after which a dryingoperation may be provided. This is a typical sequence of operations fora dishwasher.

One ditliculty that has been encountered to date is that, with. thedraining operation being provided for a predetermined period of time,the water is almost invariably removed from the machine prior to the endof the drain period. This results, with many types of pumpingstructures, in a noise which may be objectionable to some extent to theoperator. It is an important aspect of our invention that operation ofthe pump after the liquid has been removed is precluded, therebypreventing any possibility that this objectionable noise will exist. Inorder to achieve this, the timer-operated switch 33, which normallycontrols motor operation, is caused to open at the end of the firstrinse, as can be seen in FIGURE 4, as a result of the surfaceconfiguration of cam 33. This causes the motor to be de-energized, andduring this de-en-ergization, as shown by the contour of cam 34, switch39 reverses its position.

As a result, when switch 33 is reclosed the motor is reenergized but inthe opposite direction to the direction in which it rotated duringrinse. As previously described, the structure is one in which the motorprovides operation of the washing means 111 and 12- when it rotates inone direction, but operation of drain pump 15 during rotation in theopposite direction. Thus, because of the moving of switch 39 fromengagement with contact 46 to engagement with contact 47, motor 14starts up in the direction to efi'ect removal of liquid through conduit21 when switch 38 is reclosed.

Very shortly after the motor starts this operation, switch 33 is againopened by cam 33. However, because of the flow of vitiated liquidthrough conduit 21, the diaphragm 25 has caused switch 23 to move to theclosed position; as a result, motor 14 remains energized without regardto the position of switch 38. This state of atfairs continues until allthe liquid in tub 3 has been removed tirough conduit 21 by pump 15. Atthis point, when there is no further liquid being pumped through theconduit, the pressure on diaphragm 25 is relieved and the switch 23 isopened.

The timed period during which switch 38 is open is designed to insurethat the switch remains open for a longer period than pump 15 canpossibly take to drain tub This means that switch 23 moves to openposition at a time when switch 33 is still caused to be opened by cam33. As a result, the motor 14 is completely de-energizcd and remains soduring the remainder of the first drain period.

Before the end of that drain period, switch 39 is again moved by cam 34back to its original position, and at the end of the drain period switch38 is re-closed thereby to give another rinsing operation. At the end ofthe second rinse, the same thing occurs as before with respect to thedrain pump. That is, the timer causes the drain pump to start and thenreleases its control of it so that the drain pump terminates operationas soon as all the vitiated liquid has been removed through conduit 21,this being done under the control of switch 23. It will be observed thatthis sequence is followed during each drain operation throughout thecycle. This insures that the objectionable noise which sometimes occursas a result of the operation of pump 15 without any liquid being passedthrough it will not be present; thus, this phenomenon, sometimes foundobjectionable by operators, is removed from the operation of themachine.

It will be seen from the foregoing that our invention provides a controlarrangement which insures that operation of the drain pump will continueonly so long as there is liquid to be drained, and will stop thereafter,with the machine remaining completely quiescent, except for theoperation of the timer, until the next rinse or wash operation, or thedrying operation, is reached.

While in accordance with the patent statutes we have described what atpresent is considered to be the preferred embodiment of our invention,it will be obvious to those skilled in the art that various changes andmodifications may be made therein without departing from the inventionand we therefore aim in the appended claims to cover all such changesand modifications as fall within the true spirit and scope of theinvention.

What we claim as new and desire to secure by Letters Patent of theUnited States is:

1. A washing machine to provide an automatic washing cycle comprising:

(a) a tub,

(b) washing means arranged to effect washing of aricles in said tub,

(c) a drain pump to remove vitiated liquid from said tub,

(d) a drain conduit connected to said pump,

(e) sequence control means to control operation of said washing meansand said pump,

(1) said sequence control means including a first switch to energizesaid pump and initiate operation thereof,

(g) said first switch being operated by a cam means which maintains saidfirst switch closed at least until said drain conduit is filled withliquid and then opens said first switch for each operation of said pump,

(it) means responsive to liquid flow in said drain conduit including anormally open second switch cllcctive when closed to bypass said firstswitch,

(i) said means responsive to liquid flow maintaining said second switchclosed only as long as there is flow of liquid through said drainconduit.

2. In a dishwasher:

(a) a tub,

(b) washing means to effect washing of articles within said tub,

(c) a drain pump to remove vitiated liquid from said tub,

(d) a drain conduit connected to said pump,

(e) sequence control means to control operation of said washing meansand said drain pump and comprising:

(aa) a first switch to energize said drain pump and initiate operationthereof, and

(bb) cam means configurated to close said first switch until saidconduit is filled with liquid and then open said first switch for eachoperation of said drain pump,

(f) flow responsive means positioned in said drain conduit and includinga second switch in parallel with said first switch,

(g) said flow responsive means being elfective to maintain said secondswitch in closed position only as long as there is flow of liquidthrough said drain conduit.

References Cited in the file of this patent UNITED STATES PATENTS2,155,868 Pauly et a1. Apr. 25, 1939 2,288,141 Oliver June 30, 19422,953,659 Edwards Sept. 20, 1960 3,043,125 Horecky July 10, 19623,087,319 Low Apr. 30, 1963

1. A WASHING MACHINE TO PROVIDE AN AUTOMATIC WASHING CYCLE COMPRISING:(A) A TUB, (B) WASHING MEANS ARRANGED TO EFFECT WASHING OF ARTICLES INSAID TUB, (C) A DRAIN PUMP TO REMOVE VITIATED LIQUID FROM SAID TUB, (D)A DRAIN CONDUIT CONNECTED TO SAID PUMP, (E) SEQUENCE CONTROL MEANS TOCONTROL OPERATION OF SAID WASHING MEANS AND SAID PUMP, (F) SAID SEQUENCECONTROL MEANS INCLUDING A FIRST SWITCH TO ENERGIZE SAID PUMP ANDINITIATE OPERATION THEREOF, (G) SAID FIRST SWITCH BEING OPERATED BY ACAM MEANS WHICH MAINTAINS SAID FIRST SWITCH CLOSED AT LEAST UNTIL SAIDDRAIN CONDUIT IS FILLED WITH LIQUID AND THEN OPENS SAID FIRST SWITCH FOREACH OPERATION OF SAID PUMP, (H) MEANS RESPONSIVE TO LIQUID FLOW IN SAIDDRAIN CONDUIT INCLUDING A NORMALLY OPEN SECOND SWITCH EFFECTIVE WHENCLOSED TO BYPASS SAID FIRST SWITCH, (I) SAID MEANS RESPONSIVE TO LIQUIDFLOW MAINTAINING SAID SECOND SWITCH CLOSED ONLY AS LONG AS THERE IS FLOWOF LIQUID THROUGH SAID DRAIN CONDUIT.